Glass Blocks Next to Stove?

[Jeff Childers]

I am about to start a new house. Can I put glass block around a wood burning stove? I am pretty sure the glass blocks themselves would survive, but I wonder about the grout around the blocks and whether the plastic alignment system that gets covered by the grout will survive.

Have you ever seen anyone use glass block in their stove surrounds?

Can I crowd the combustable material distance limits when using glass blocks near the stove?

Does using glass create a safety problem? I would hate to lean up against a hot piece of glass.

Thanks,
Jeff

 

[restorer]

I'm not about to place judgment, but take a few glass bricks and set them near a 4-5oo degree fire and see what they do. Glass is not an insulator, the air inside the bricks will expand, if the heat is not immediately dissipated the expansion of the air will not be matched by the expansion of the glass. You will get?????

Personally, I have seen glass bricks shatter from too much sun light on a winter day. Extreme heat and glass bricks don't mix. A friend who did Trombe walls for solar heating in Greeley, Colorado has spent a lot of time replacing glass brick with adobe in the last fifteen years. Don't take the salesman's pitch.

 

[MountainStoveGuy]

i cant speak of the glass brick's. Uncles explination seems convincing enough, but. I would assume, by the way the code is written, that the glass bricks with a 1" airspace between the bricks and the combustable would give you 66% reduction. Thats the techical explination, not the logical one.

 

[Corey]

My gut reaction is that it doesn't sound like a good idea...Although I thought the glass blocks were formed from two halves which are fused together in the center. With that being said, if the glass halves are fused together, I would think the air inside would be close to the temperature of melting glass when the seal is made and would probably be under vacuum unless you got the temperature back close to that level?

Uncle seems to indicate that he has seen blocks shatter due to a warm sunny day. I have seen walls, storefronts, windows, etc built from glass blocks, and personally built a shower wall out of them and haven't ever known any to shatter, but I wouldn't doubt his experience. I would be curious, though, if the breakage was due to some factor of the installation as opposed to simple thermal stress?

Corey

 

[Gooserider]

I'm no expert on the subject, but I suspect that there are two ways of doing glass brick walls - one is the old fashioned way with some sort of masonry, and the other is using some of the new-fangled plastic and aluminum stuff to set them up, with silicone adhesives, etc. Just guessing, I would suspect that the older techniques might be more heat resistant and therefore "better" than the newer ones.

What I would suggest doing is to get a manufacturers name off whatever system you are planning to use, and then contacting their technical department, and asking for a written opinion on the suitability of their products for your application - specifcially things like heat resistance, clearances, if they would be classed as non-combustible, etc. Also ask if the product would be covered under any applicable warranties when used for your application. Get all this in writing....

Gooserider

 

[restorer]

Thought I would explain the shattering. In a former store I had the building was remodelled by the owner who was a tile man. He tried glass bricks on the South side of the foundation wall to let light into the basement. He then ran a forced air heater across the ceiling with a 12 X 16 duct to within 2 feet of the wall. Over the weekend the temperature dropped to single digits and a strong south wind packed ice and snow against the wall. When we cranked the heat up the sudden change and difference between the outside air and the inside shattered the inner side of the bricks. Thought that was bad enough, but over the Summer, with refrigerated air inside the building a 115* heatwave shattered the outside of the bricks. Too much temperature difference on the two surfaces.

My friend in Greeley uses a wall for passive solar to store heat. He used glass brick and stained glass to dress up the walls. Both have failed because the glass can not handle the high temperature differentials.

I am not saying you might not be able to get by, but I wouldn't want to rework the walls at todays costs.

 

[Jeff Childers]

Thanks to all of you! I appreciate your advice.

I think I will forget the glass wall around the stove. It might work, but I guess I don't have a stomach for the risk involved. Besides, why would I want a pretty wall around my stove? It would detract everyone from noticing how cool and nifty my stove is. Ha!

Jeff